Allergic reactions to drugs are immune reactions that occur in a small number of people who have previously taken the drug. Allergic reaction can occur to any medication.
Drugs that most often develop allergic reactions are: antibiotics (penicillins, cephalosporins, carbapenems), acetylsalicylic acid and related drugs, nonsteroidal antirheumatic drugs, sulfonamides, nitrofurantoin, anticonvulsants and anesthetics.
The route of administration, the duration of treatment, the dose and the frequency of drug administration influence the occurrence of drug hypersensitivity reactions.
In the diagnosis of drug allergy, we use laboratory tests (determination of specific IgE antibodies to drugs, basophil degranulation tests, lymphocyte proliferation test) and skin testing.
Skin tests are the most available diagnostic method to confirm or rule out sensitization to a particular allergen, and thus to a drug. Their diagnostic value has not been fully evaluated for all drugs.
It is recommended to perform testing to drug within a period of 4-6 weeks, up to a maximum of 6 months after a suspected reaction to the drug, in order to reduce the possibility of false negative results.
If there are negative laboratory findings and skin tests to the drug, it is necessary to do a provocation /exposition test with the drug in order to definitively exclude hypersensitivity/allergy to the drug.